1. Technical Field
This invention generally relates to riding cement surface working machines and in particular to a trim control for zeroing the control linkage to compensate for differing weight distributions experienced due to different riders.
2. Background Art
A typical two rotor riding surface working machine for finishing cement is taught by HOLZ, SR., ET AL., U.S. Pat. No. 4,046,484. Holz teaches a riding machine having two overlapping intermeshed rotors where the motion of the machine is controlled by a single control stick by a seated operator. Dual control sticks are also known and used in the art. For details on the locomotion and direction control of these machines, reference is made to U.S. Pat. No. 4,046,484, to HOLZ, SR., ET AL.
In general terms, the locomotion and direction of a riding surface working machine, also here referred to as a riding power trowel, is determined by circumferential pressure points of the two rotor assemblies against the working surface. Consequently, the operator must maintain a riding posture such that his center of gravity is coincident the center of gravity of the riding power trowel in order to prevent undesirable pressure points caused by an unbalanced rider and machine.
Unfortunately, riding power trowel operators come in various sizes and shapes and certainly each have various preferred postures. As it is impractical to custom design a riding power trowel to compensate for varying riders' weight and preferences, manufacturers have heretofore left it up to the operator to compensate his posture accordingly. This presents a significant problem to persons while learning to operate a riding power trowel and can be very uncomfortable to the experienced user. If not compensated for, an unbalanced machine will demonstrate sluggish and possibly erratic performance.
What is needed is a device capable of compensating for the differing weight distributions demonstrated by different operators.
Accordingly, it is an object of the present invention to provide a trim control to a riding power trowel thereby giving the operator the ability to adjust the balance of the machine to compensate for his particular weight distribution. It is a further object of the present invention to provide a trim control which can be adjusted by the operator while the machine is in operation.